1. Field of the Invention
This invention relates to a novel compound useful as a herbicide for agriculture and horticulture, to a herbicidal composition containing the same, and to methods of controlling weeds and the production thereof.
2. Description of the Prior Art
In recent years, a number of herbicides have been developed and put into practical use. These herbicides have contributed to a saving of labor and increased agricultural production. However, there is still room for improvement, and novel chemicals which have reduced effects on useful cultivated plants but have a strong herbicidal action on undesirable plants and which are very safe in regard to environmental pollution have been desired. For example, phenoxyalkanecarboxylic acids represented by 2,4-dichlorophenoxyacetic acid, which have been known for a long time, have superior controlling effects on broad-leafed weeds and find widespread use. However, since phenoxyalkanecarboxylic acids have only a slight activity on gramineous weeds which are commonly encountered noxious weeds, and are phytotoxic to broad-leafed plants which embrace many crops and cultivated trees, these chemicals only have limited application.
Diphenyl ethers represented by 2,4-dichloro-4'-nitrodiphenyl ether have recently gained wide acceptance, but their selectivity in exterminating noxious weeds is insufficient.
The 4-phenoxy-phenoxyalkanecarboxylic acids recently proposed in West German Patent Application No. p2223894/1972 exhibit some degree of improved selectivity, but suffer from the defect that their herbicidal activity is insufficient.